Some of these may apply to other autistics, some may not, we're all different, there is no standard autistic, just as there is no standard neurotypical person. But before you interact with someone like me, here are a few things you need to know:
A: NO, you most likely do not perfectly understand those who are autistic in terms of emotions and what we're thinking, you probably think you do because you are used to being surrounded by neurotypical people who are like you and so are easy to read and therefore you assume you have universal empathy. The biggest issues I have are with people who think they "get" me, when in fact, they might as well be claiming to "get" Russian while not speaking a lick of it because they speak English and English is related to Russian. Usually people who think they "understand" have the least chance of actually being so much as minimally aware of my basic humanity never mind anything more complicated like how my mind actually works.
It's easy to get people who are like you, it's even easier to assume you get people who are not like you when in fact you can't because you're too busy believing you do to actually do so.
Seriously, even I don't always get all autistics and I have observed that often Neurotypicals don't always get each other, yet still people who have about as much insight into my mindset as a fish does of mars think that they actually do have insight and will blindly plow ahead based on that belief then get pissed, when they're corrected.
B: First things first, if you truly want to understand with someone with an autistic mind, well to understand requires listening, the number one mistake people make is not to listen and to just assume they understood. I have had so many people grab the wrong end of the stick because they assumed they understand everyone, didn't listen past the first couple of words and then they proceed to do the conversational equivalent of anally reaming themselves with said stick because they won't actually do what is needed to talk to and to understand someone like me and then they blame me for the fact that they basically epically fucked their ability to be able to sit comfortably through their own actions.
C. Learn that any criticism is not personal hate of you. It's not unusual when in a group of people like myself, that deep and long conversations take place about an item, including pointing out the bad bits. It's like talking about the weather for someone like me. I don't hate the weather when I say I don't enjoy overcast days, equally well I don't hate you just because I honestly tell you what I think about something that may be near and dear to your heart.
There is no more emotional context attached to my critique, than there is to me saying "the door is blue". It's a statement of fact for me. Neurotypical people often get in a right snit and decide people like me are hateful because one of us has said something like "I do not like green" when it's the NT person's favourite color. If I hated everything I criticised, I'd be exhausted.
D. As an autistic I am complete mindblind to a number of things, these include subtext, emotional manipulation, and similar subtle things. I'm also face blind, I might be good friends with them, and yet walk straight past them in the street. That is what it is like for me in conversations, I might entirely miss a subtext implication you make unless I'm very familiar with the implication and recognise it, equally well I cannot add subtext to what I say because I am blind to it and there's no real way to learn to use it, therefore if you try to read what is literally not there, you'll end up with what typically is a reflection of you, not anything from me. Please for a love of everything, remember this.
I cannot stress this enough. Trying to read subtext in a subtext blind person's writing is like taking a braille letter from a blind person and claiming you can read non-braille words by joining the dots up to make distorted english letters. It doesn't work, you just end up pissed off, I end up rather frustrated with you, and everyone's unhappy.
E. If you are nasty to me, know that interacting with you can trigger flashbacks to the earlier nastiness for me, complete with all the emotions, it's literally like it's happening again to me. This is involuntary, if you feel miffed that I haven't forgotten you calling me a nasty name a month ago, and feel I should have gotten over it, even though you never apologised, remember that for me sometimes when I deal with you, it's as if every nasty thing you have done is happening again for me.
It's the way my mind works, I might forget whatever shitty thing someone did for months or years, then I hear their voice and am deluged in the original event, it makes it very hard to forget especially when there are lot of incidents when people have been outright nasty to me over a period of time.
On the flipside, I also have good flashbacks, so if you've since apologised to me, or behaved cordially towards me to the point where I've had more good experiences than bad relating to you, I will remember that as well, and feel warm towards you all over again even if we're arguing at the time. In short, how you behave towards me has a major impact on me when interacting with you even months and years later.
F. I will give you an honest answer even if you don't want one. I cannot pick up on the "lie to me" cues and to be honest, I'm a lousy liar so I don't bother lying, plus I have issues with lying due to having a chronic liar in the family, it makes me anxious so don't ask me to lie for you.
Do not ask a question unless you're willing to accept an answer you may not like, or appreciate. I am not a sounding board, and to be honest, I care more about liking myself then about fooling all of you to like me by being something I'm not.
G. Again, do not expect me to read your mind. I may grasp your mindset better than you can grasp mine, just due to exposure to so many neurotypical people. But I am still not a mind reader, add in the blindness that comes with Autism and if you expect me to pick up on subtle cues, I will disappoint you.
H. Don't be afraid to interrupt me or to physically walk away if you tire of the conversation. I will not consider this rudeness. Equally well be aware that if I do this, I am not trying to be rude, I am probably overloaded with information and need a break.
I. I have autism and a mental illness. However this does not mean everything I do is a symptom of having them. Especially when you've just said something horribly bigoted or done something abusive towards me and I object.
This kind of thinking usually goes hand in hand with people in power deciding that our complaints can't have validity because we're "crazy" or "aggressive and lashing out because we're autistic and frustrated", it has resulted in a lot of abuse of people like me when we have been deemed too crazy or aggressive to know we're being abused even when if the same thing was done to a "normal" person it would be considered abuse. If everything people do that we don't like was a function of their neurology, being an asshole would be considered a major symptom of being "normal" to be blunt.
If I find your comments inappropriate or hurtful, it is typically not because I'm crazy, unreasonable or too autistic to understand, it's typically because you said something that was inappropriate or hurtful.
That's the basics.